b13

Question 1

electrical impulses in neurons

Answer 1

travel along neurones to transmit information quickly from one part of the body to another.

Question 2

What does CNS central nervous system consist of?

Answer 2

brain and spinal cord

Question 3

what does CNS do?

Answer 3

processes information and coordinates responses

Question 4

what does PNS do?

Answer 4

carries messages to and from the CNS (all nerves outside CNS)

Question 5

role of the nervous system?

Answer 5

-coordinates body function
-regulates body functions

Question 6

types of neuron

Answer 6

-sensory
-relay
-motor

Question 7

sensory neuron

Answer 7

carries impulses from receptors to the CNS

Question 8

relay neuron

Answer 8

found in the CNS; connects sensory and motor neurones

Question 9

motor neuron

Answer 9

carries impulses from the CNS to effectors (muscles or glands)

Question 10

reflex arc

Answer 10

a rapid, involuntary response to a stimulus.

Question 11

reflex arc pathway

Answer 11

Stimulus → receptor → sensory neurone → relay neurone (in spinal cord) → motor neurone → effector → response

Question 12

receptor

Answer 12

detects the stimulus

Question 13

effector

Answer 13

produces the response(muscle contracts or glands secret)

Question 14

photoreceptors

Answer 14

detect lights

Question 15

mechanoreceptor

Answer 15

hearing

Question 16

temperature

Answer 16

thermoreceptor

Question 17

smell and taste

Answer 17

chemoreceptors

Question 18

hormones

Answer 18

a chemical substance, produced by a gland, carried by the blood, which alters the activity of one or more specific target organs.

Question 19

endrocine glands

Answer 19

are glands that secrete hormones directly into the blood rather than through a duct

Question 20

adrenal glands

Answer 20

adrenaline

Question 21

testes

Answer 21

testosterone

Question 22

ovaries

Answer 22

oestrogen

Question 23

pancreas

Answer 23

glucagon and insulin

Question 24

adrenaline

Answer 24

a hormone produced by the adrenal glands when the body is in a ‘fight or flight’ situation.

Question 25

adrenaline effects

Answer 25

Increasing breathing rate → more oxygen for muscles Increasing heart rate → faster blood flow to muscles Increasing pupil diameter → better vision

Question 26

homeostatis

Answer 26

is the maintenance of a constant internal environment in the body, despite changes in the external environment.

Question 27

negative feedback

Answer 27

occurs when a change in a condition triggers responses that reverse the change to bring it back to the set point.

Question 28

What happens when there is high blood glucose concentration?

Answer 28

Insulin is secreted by the pancreas → glucose is converted to glycogen in the liver → blood glucose falls.

Question 29

what happens when blood glucose conc is low?

Answer 29

glucagon is secreted by the pancreas → glycogen in the liver converted to glucose → blood glucose rises.

Question 30

beta cells

Answer 30

detect high glucose and release insulin

Question 31

alpha cells

Answer 31

detect low glucose and release glucagon

Question 32

hair erector muscle

Answer 32

raise hair when scared or cold to trap air for insulation

Question 33

sweat glands

Answer 33

Produce sweat → cools the body by evaporation.

Question 34

blood vessels

Answer 34

Supply nutrients and help regulate body temperature (vasodilation/vasoconstriction).

Question 35

fatty tissue

Answer 35

Acts as insulation and energy storage.

Question 36

insulation

Answer 36

prevent heat loss

Question 37

insulation in mammals

Answer 37

Hair/fur traps air, reducing heat loss. Fatty tissue provides insulation and stores energy.

Question 38

sweating

Answer 38

Sweat glands produce sweat. Evaporation of sweat from the skin removes heat, cooling the body when hot.

Question 39

shivering

Answer 39

Muscles contract involuntarily when cold. Contractions produce heat to raise body temperature.

Question 40

role of brain in hot or cold

Answer 40

The hypothalamus acts as a thermostat

Question 41

vasodilation

Answer 41

arterioles near skin widen → more blood flows near surface → heat lost → cools body.

Question 42

vasoconstriction

Answer 42

arterioles near skin narrow → less blood flows near surface → heat retained → warms body.